1. Field of the Invention
The present invention relates to a method of manufacturing a vehicle body on a space frame using specialized fasteners to form an integral shim between body panels and the space frame.
2. Background Art
Vehicles may be manufactured on a conventional frame, a space frame or with an integral frame (unibody construction). Conventional frames have a chassis at the base of the vehicle body to which body panels are secured by welding or fasteners. A space frame vehicle has a cage-like frame to which body panels are secured with fasteners. A unibody vehicle has frame components formed into the floor pan and other body panels. The present invention focuses on solving problems relating to the manufacture of space frame vehicles.
Space frame vehicles are built on a space frame to which body panels are attached. Variations in manufacturing space frames is caused by part tolerance stack up, heat distortion or other reasons. Space frames may be warped, twisted, or otherwise not in conformance with body locator specifications. If the frame does not conform to body locator specifications, it may be difficult or impossible to accurately and securely fasten body panels to the space frame. The prior art relied upon the use of shims or shim packs to fill gaps and provide a good fit between body panels and the space frame to compensate for space frame variations.
The use of shims or shim packs in manufacturing a space frame vehicle is a laborious process. Gaps between body panels and space frame fastener mounting locations must be measured and shims must be selected that are of the proper height to fill any gaps. The shims then must be inserted while the body panel is secured to the space frame. The use of shims is also somewhat inaccurate since it relies upon manual measurements and the judgment of assembly line personnel to select the proper shim size. If a shim is not the correct size it may become loose or even fall out. If this happens the body and space frame may suffer from unnecessary noise and vibration.
There is a need for a cost effective and precise method of manufacturing a vehicle using a space frame that eliminates the use of shims. There is also a need for an automated manufacturing system for accurately and securely locating body panels on a space frame.
The above problems and needs are addressed by applicant's invention as summarized below.